class_docstr: **Bases:** :class:`GLGraphicsItem <pyqtgraph.opengl.GLGraphicsItem.GLGraphicsItem>`
  
  Displays image data as a textured quad.
code: def initializeGL(self):
      if self.texture is not None:
          return
      glEnable(GL_TEXTURE_2D)
      self.texture = glGenTextures(1)
  
file_path: pyqtgraph/pyqtgraph/opengl/items/GLImageItem.py
imports: from OpenGL.GL import *
  import numpy
  from ..GLGraphicsItem import GLGraphicsItem
label_desc: Use image node_id 2 for calling the GLImageItem obj's underlying member method code with example usage: obj.initializeGL() without return types